Kaplan Nursing Entrance Practice Exam

Sound waves are classified as which type of wave?

1. Transverse wave

2. Longitudinal wave

3. Mechanical wave

4. Seismic wave

The correct answer is: Longitudinal wave

Sound waves are classified as longitudinal waves primarily because of the way they propagate through a medium. In longitudinal waves, the displacement of the medium's particles occurs in the same direction as the wave’s travel. This results in alternating areas of compression and rarefaction, which corresponds to areas where particles are pushed together (compression) and pulled apart (rarefaction). This characteristic is fundamental to sound waves, which require a medium such as air, water, or solids to travel through. As sound energy passes through these mediums, particles vibrate back and forth along the direction of the wave, exemplifying the longitudinal wave motion. While sound waves can also be considered mechanical waves—since they need a medium to propagate—defining them specifically as longitudinal captures their distinct mode of propagation, differentiating them from transverse waves where particle motion is perpendicular to the direction of wave travel. Understanding this distinction is crucial in various fields, including physics and acoustics. It's also important to note that seismic waves, while they can include sound waves within the Earth, encompass different types of waves, including both longitudinal and transverse, depending on their behavior during seismic events.